Conventionally, in a lithography process for producing electronic devices (microdevices) such as liquid crystal display devices and semiconductor devices (integrated circuits), apparatus are used such as an exposure apparatus of a step-and-scan method (a so-called scanning stepper (also called a scanner)), which transfers a pattern formed on a mask on a substrate using an energy beam while a mask (photomask) or a reticle (hereinafter referred to collectively as a “mask”) and a glass plate or a wafer (hereinafter referred to collectively as a “substrate”) are synchronously moved along a predetermined scanning direction (scan direction).
As this kind of exposure apparatus, an exposure apparatus is known with an optical interferometer system that acquires position information within a horizontal plane of a substrate subject to exposure, using a bar mirror (a long mirror) that a substrate stage apparatus has (for example, refer to PTL 1).
When position information of the substrate is acquired using the optical interferometer system, influence of the so-called air fluctuation cannot be ignored. Also, although the influence of the above air fluctuation can be reduced using an encoder system, the increasing size of the substrate in recent years makes it difficult to prepare a scale that can cover the entire moving range of the substrate.